The Study Of Fuzzy Sliding Mode Control And Its Application To Semi-active Suspensions In Vehicle

Suspension is one of important component of vehicles,which has tremendous relationship on performance of ride quality and handing stability. Suspension system can be divided into passive suspension, semi-active suspension and full active suspension. It is difficult for the traditional passive suspension which has fixed parameters by optimization to adjust them to improve on the ride comfort and the road changes. Active suspension to need to rely on plus force to control itself, but it will improve energy consumption and the increase of vehicles own weight. Semi-active suspension compared active suspension; it is composition by elastic components and damping adjustable shock absorber and has many advantages including simple structure, low energy consuming, easily realizable. So it has a broad prospect of application because of performance and close to active suspension.It is very important to design system control strategy which as the whole semi-active suspension system control technology at the core for suspension characteristics influence. Sliding mode control has gained wide applications for the strong robustness of system model for non-precise and external disturbances. But the sliding mode control of discontinuous switching bring the high-frequency chattering phenomena have become the main obstacle restricting its application. Fuzzy control as by expert knowledge and experience of the effective method is suitable for complicated, nonlinear and time-varying system especially. But most of the fuzzy control system lacks guarantee system. Fuzzy control and sliding mode control can complement, and get better control effect.In this paper, a quarter car with two degrees of freedom semi-active suspension system will as control object, and the skyhook system as the reference object. First, the semi-active suspension and Skyhook System dynamic model are established in Matlab/Simulink software. Then, the sliding mode controller and fuzzy sliding mode controller were designed, and simulation analysis used of Matlab software. Finally, contrast all simulation results, to verify the effectiveness of the controller. This study can improve automobile semi-active suspension system performance, to provide reliable technology guarantee for improving the automobile suspension design level and for the future and comprehensive research automobile driving performance laid the foundation.